org.apache.kafka.streams.state.internals.OrderedBytes Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.streams.state.internals;
import org.apache.kafka.common.utils.Bytes;
import java.nio.ByteBuffer;
class OrderedBytes {
private static final int MIN_KEY_LENGTH = 1;
/**
* Returns the upper byte range for a key with a given fixed size maximum suffix
*
* Assumes the minimum key length is one byte
*/
static Bytes upperRange(final Bytes key, final byte[] maxSuffix) {
final byte[] bytes = key.get();
final ByteBuffer rangeEnd = ByteBuffer.allocate(bytes.length + maxSuffix.length);
int i = 0;
while (i < bytes.length && (
i < MIN_KEY_LENGTH // assumes keys are at least one byte long
|| (bytes[i] & 0xFF) >= (maxSuffix[0] & 0xFF)
)) {
rangeEnd.put(bytes[i++]);
}
rangeEnd.put(maxSuffix);
rangeEnd.flip();
final byte[] res = new byte[rangeEnd.remaining()];
ByteBuffer.wrap(res).put(rangeEnd);
return Bytes.wrap(res);
}
static Bytes lowerRange(final Bytes key, final byte[] minSuffix) {
final byte[] bytes = key.get();
final ByteBuffer rangeStart = ByteBuffer.allocate(bytes.length + minSuffix.length);
// any key in the range would start at least with the given prefix to be
// in the range, and have at least SUFFIX_SIZE number of trailing zero bytes.
// unless there is a maximum key length, you can keep appending more zero bytes
// to keyFrom to create a key that will match the range, yet that would precede
// KeySchema.toBinaryKey(keyFrom, from, 0) in byte order
return Bytes.wrap(
rangeStart
.put(bytes)
.put(minSuffix)
.array()
);
}
}